Flow Induced Vibration Prevention and Resolution

All process plants exhibit flow induced vibration to some degree in their piping systems. This may lead to process outages, reduced flowrate restrictions or failure in some cases. Here we discuss how to head off problems at the design stage and how to address problems once found. The Problem Unsurprisingly, vibration of piping causes stresses … Read more

How to: ‘Quick and Dirty’ FFS of Fittings

Assessing fitness for service of pipe fittings is tricky. Whilst we’d encourage you to assess them carefully, what about when you just want to know if you should expend the effort to do more detailed analysis or FEA ? Here is a simple approach that can sometimes be employed when you need a first pass … Read more

‘Hot sustained’ stress – comparison of methods

In the past few years there has been an increased focus on the so-called ‘hot sustained’ stress in piping system analyses. The ASME B31.3 2006 edition clarified that Sustained stress requirements must be met for all operating conditions of a piping system. There had always been practitioners whose view was that any stress due to change in temperature should … Read more

B31.3 Code Issue – Non-conservative Sustained Stress

I would like to highlight an issue in ASME B31.3 that’s been sitting there underneath most of our noses for several years. Depending on your interpretation of the Code (or that of your pipe stress software) this can result in significant under-prediction of sustained and occasional bending and torsional stresses at reducing intersections. [Edit March 2017: … Read more

Salad Post-Processor for CAESAR II

Salad works with pipe stress analysis data from CAESAR II by Intergraph, to help you prepare ancillary reports and calculations.  It can even work as an automated ‘bridge’ to your existing or new spreadsheets. Salad can also be used for standalone calculations as an alternative to spreadsheet or math applications. Template scripts are provided to … Read more